1. Field of the Invention
This invention relates to electric discharge lamps and has particular reference to an improved fluorescent lamp of double-ended construction that is of compact size and constitutes a concentrated light source of high brightness when energized.
2. Description of the Prior Art
Electric discharge lamps having envelopes which are internally partitioned to provide one or more elongated discharge paths are generally well known in the art. U.S. Pat. No. 2,121,333 issued June 21, 1938 to Barclay discloses a single-ended discharge lamp having glass panels which are joined to the glass envelope and serve as the partition means. A single-ended fluorescent lamp having a tubular envelope that contains a partition comprising a glass or ceramic panel, or one which is fashioned from a stiffened sheet of fiberglass or the like, is disclosed in U.S. Pat. No. 3,024,383 issued Mar. 6, 1962 to Doering. The partition component is supported by a disc-like base member that is seated on top of the stem and extends to the envelope wall.
Flat or panel-like fluorescent lamps having partitions that are fabricated from sheet metal which is coated with a phosphor are also known in the art and are disclosed in U.S. Pat. No. Re. 22,896 issued July 8, 1947 to Polevitzky and U.S. Pat. No. 3,508,103 issued Apr. 21, 1970 to Young, the author of the present invention. An electric discharge lamp of single-ended construction having an envelope that contains an arc-enclosure consisting of metal baffles and light-transmitting side panels that are secured to a stem and define a tortuous path for the arc is disclosed in U.S. Pat. No. 2,030,715 issued Feb. 11, 1936 to Pirani et al.
Fluorescent lamps of double-ended construction having a plurality of electrodes at each end and a partition structure that divides the envelope interior into several independent arc channels which extend directly between opposed pairs of electrodes are disclosed in U.S. Pat. Nos. 3,084,271 issued Apr. 2, 1963 to Swanson and 3,194,997 issued July 13, 1965 to Waly.